As the name suggests, some auctions will allow you to instantly purchase an item instead of bidding on it (just like "Buy It Now" on eBay).

There are pros and cons for both sellers and buyers with this system. For sellers, the pros include setting a reasonable Buyout may entice someone to grab the item before the auction ends. You may be able to get a slightly higher price from those who need an item right away and are willing to pay for the privilege. It is in your best interest to always include a buyout price. The only real con of setting a Buyout price is that you may set it too low and someone will snap it up and possibly turn around and sell it for more.

For buyers, the main benefit is obviously getting the item instantly. You may also run into items that have a lower than average Buyout price. In this case, you may actually be able to make some money off the item yourself by buying it and re-listing it at its "proper" or more competitive price.

Bidding works like any auction: you put in the price you are willing to pay, someone else can come along and outbid you. The person with the highest bid at the end of the auction wins the item.

Just because an auction starts low does not mean that it won't skyrocket toward the end. Keep in mind that some sellers intentionally try to create a bidding war. Before you begin bidding, have a final price in mind. No matter how tempting it may be, don't go over that price - you may end up paying more than you wanted or more than the item is worth!

A seller can cancel an auction at any time, although they will lose the initial deposit (and if the item has been bid on, they will also be charged a percentage of the bid).

If you want to buy an item that has been listed with no buyout price, you can try to contact the seller directly and make an offer. You can also try this with costly items (especially a weapon or armor piece with a high deposit cost and relatively low demand). The seller may agree, especially if they're afraid the item won't sell or if they need money right away.

You should set most auctions to run 48 hours to maximize your auction's exposure. Remember, although the deposit is larger for longer auctions, your deposit will always be refunded if the auction sells.

Sometimes, you'll want to list auctions for 12 or 24 hours, especially if the deposit is prohibitively high (this is especially true for weapons) and if you're afraid demand might not be there. If you are sure that something will sell relatively fast, 24h is a less costly option. If you do so, make sure you list the auction during peak hours on your server. Player activity usually peaks between 6pm and 9pm and is higher on weekends. See (Time) for more details.

Keep in mind that if you have a costly item that may not sell, it may be smarter to use the trade channel rather than using the auction house at all.

Pricing an item can be difficult for those new to the Auction House. A good way to find out what something is worth is by searching for an identical item already posted. There may be several of the same item already up for auction, their prices should give you a rough idea of what the item is worth.

However, there may not be any other items of what you are looking to sell currently on the Auction House. If this is the case, you can search for something similar. For instance, some items are part of a series, such as "Fringed Cloak of the Bear" or "Fringed Cloak of the Eagle". If this is the case, try a search for just "Fringed Cloak" and it will bring up the items in a series. This will give you an idea of what your item is worth, even though the exact one may not be listed.

If you cannot find any similar items, you have a few more options. One is to go to a vendor and see how much they will give you for the item (don't sell it to them, just hover your mouse over the item to see what it is worth). You can normally get several times the amount the vendor will give you in the Auction House. So go back and post it for 3-10 times the vendor amount.

You could also just post the item with a relatively low starting bid (don't put a Buyout price on it though), likely the item will be bid up to about what it is worth by the end of the auction.

Alternatively, you can just wait until you see a similar item on the auction house, or ask around - your guild mates are a great resource!

You may choose to post your auctions from an alt. There are several advantages to this.

First, you can leave your alt in a major city and mail your items to it, so that your other characters don't have to travel back and forth. As your other characters obtain items that you wish to auction, it is easy to just drop those items into the nearest mailbox for your auction house mule to pick up later, thus freeing up precious bag space. Recent patches have removed the time delay for mailing items between your alts, so your items will be available for auctioning right away.

Secondly, having an auction house mule allows you to keep your auction house inventory separate from the items that your other characters have in their inventories. You don't have to remember which items are flagged for posting or re-posting, or organize your inventory to keep those items separate. Auctions that don't sell will come back to the auction house alt, instead of back to your main.

Finally, using an auction house alt also provides you anonymity. It's possible that if you are involved in heavy trading or practices that some see as ethically questionable (such as trying to corner a market) some players may hold it against you. Therefore your alt can protect your main's reputation. (On the other hand, 95% of your potential buyers either never pay attention to the names attached to the auctions or simply don't care.) Posting auctions from an anonymous mule also prevents whispers at inconvenient times from other people to ask about items that you have posted.

Twinks often seek out the best possible items that they can equip at their current level. These items are always in high demand at the Auction House. Battleground twinks especially will pay high prices for the best items usable at level 19, 29, etc. If you come across one of these items, especially BoE rare items with good PvP qualities, you will get a very good amount of money by selling it via the Auction House.

Sometimes a scammer will repeatedly post a piece of vendor trash or another less-than-valuable item at extremely high prices. The idea is to get people who are scanning with Auctioneer or other AddOns to collect this bad data. Then the scammer will post the item for a much lower (but still expensive) price, hoping to bait others into buying what they think is a good deal.

To avoid this, never buy something unless you know exactly what it is.

Sometimes you'll see common items like trade goods listed for extremely high buyouts, like Strange Dust for 100 gold.

There are two ideas behind this scam. First, the scammer hopes some poor fool will click on the auction by accident or not notice the erroneous price. This may not happen very often, but when it eventually does, the scammer makes a lot of money.

Another version of this scam has the scammer setting a very low starting bid but high buyout. For example: Heart of Fire for 1 bid and 100 buyout. The scammer hopes that in the ensuing bidding war, someone will accidentally click "buyout" instead of "bid." However, this scam is more risky because it requires an item that is at least somewhat valuable. Plus it is less likely to happen now because there is now confirmation box before a buyout is made.

Sometimes people check the AH for blue or epic items that are the only ones who are being sold at that moment. They buy the item, repost it on an ALT for a much higher price. Then they logon to another character and start typing in trade: "WTB <item in question> for xxxG", where xxx is 50G or so over the buyout price of the item in question. People who know that there is such an item for sale at the AH might buyout that item (giving the scammer a nice profit) thinking to make a nice bundle of money. The scammer then invents some reason not to buy the item.

Many items in the game use the same icons as one another -- occasionally a person offering to trade a rare item will replace this item with an extremely common item that uses the same icon when trading. To counter this, make sure to mouse over any item placed in the trade window to make sure it is the correct item.

Trade windows include a slot at the bottom that will not trade the item in question. This slot is used for placing enchantments or enhancements on a person's equipment, including soulbound items. Occasionally people will try to trade an item within this slot, accepting payment without trading the item itself. To prevent this, make sure that none of the items for trade are in the 'will not be traded' slot.

The reverse of this trick to offer or sell an enchant, but then insist that the item to be enchanted be traded rather than placed in the "will not be traded." A new player might not understand that enchants can be applied through the trade window and hand over the item, never to see it again. Many valuable items will be soulbound and unable to be traded in this way, but some non-binding items can be sold for good prices for varying reasons. Be sure to always use the "will not be traded" for item enchants.

When selling items, the buying participant will sometimes change the amount of gold offered — usually by a factor of ten — after the seller has confirmed it. For example, the buyer might change 600 gold offered to 60 gold right before finishing the trade. This will de-confirm the window — however, the change is not obvious, and the deconfirmation happens for many unimportant changes, so people will usually re-confirm anyway and lose out on potentially hundreds of gold. To counter this, make sure to thoroughly check the transaction if the confirmation ever gets de-confirmed.

On most servers, player activity peaks at 6pm to 9pm. It is usually at its lowest point around 6am. If you're running mostly 24 hour auctions with buyouts it doesn't matter when you post your auctions. If you're relying on bids, or trying to post short auctions, it's best to do it when players are most active. Check your servers' time zone to find out when most players will be on. Often, server time and your time will be different, leaving you trying at the wrong hours.

On weekends, (Friday, Saturday, Sunday) and holidays, player activity is significantly higher. Apparently Monday and Tuesday are the lowest activity days, since Blizzard put weekly maintenance on Tuesday mornings. This has led to many theories about when to post auctions.

Some theorize that Sunday is the best day to post auctions for armor and weapons because casual players have just finished a weekend of levelling up and will be looking for new gear.

Likewise, prices for trade goods may drop on weekends as less informed players all try to undercut each other. On the other hand, demand for these goods also rises on weekends. On weekdays there's a better chance that someone (or yourself) will try to create a monopoly on certain trade goods, driving prices up. Therefore, weekends are (sometimes) good for buying trade goods and weekdays are good for selling them.

Some professions have a relation to player activity, like jewelcrafting. Players that loot new gear will often need new gems. You are likely to sell more gems on evenings that guilds raid (can be both weekend and weekdays, but especially Wednesday and Friday). A smart time seems to be to post your gems around 20:00-22:00, since a lot of your competition will be raiding, so won't undercut you after you posted, and raids end about 21:30-00:30. Keeping an eye on what nights big guilds raid, and how active the LFG channel is, together with some experience, can help you pick good times.

On some Monday night/Tuesday morning(US) or Tuesday night/Wednesday morning (Europe), realms go down for several hours for maintenance. Auctions, however, still expire.

Don't post auctions on a day before maintenance, unless you don't mind losing a lot of your auction's duration.

If you bid on an auction with a short or medium duration remaining right before the server shuts down, you will win that auction because no one else will be able to bid on it.

There's only one problem with this strategy: other people are also doing it. The time before shutdown is very active, with a few players furiously bidding on the good deals. It's exciting, but you'd actually win just as many auctions by bidding on other nights, when fewer people are paying attention.

Whenever a special event such as a holiday occurs, pay attention to any items that can be traded. Things with limited availability may become more valuable as time passes. Special events may also be: new arena season (new gear), game patches/content extensions, etc.

Also pay attention to items required by new quests. When the Feast of Winter Veil appeared, the quest Treats for Greatfather Winter asked players to obtain Ice Cold Milk. Shockingly, many players didn't know or perhaps didn't care that the milk could simply be bought from a vendor. For a very brief time, milk was actually selling on the auction house for a hundred times its actual value. Much more lucrative was the jump in demand for certain trade goods when the Tier 0.5 quests were introduced. Keep an eye on reports from beta testing to predict future opportunities of this nature.